Flow rate control mechanisms are used in a wide variety of flow systems for controlling the amount of fluid, gaseous or liquid, traveling through the system. For example, a flow rate control mechanism may be used to affect chemical reactions by helping to ensure that proper feed stocks, such as catalysts and reacting agents, enter a processing unit at a desired flow rate. In another example, a flow rate control mechanism may be used to regulate flow rates in systems such as ventilators and respirators where, for example, it may be desirable to maintain a sufficient flow of breathable air or provide sufficient anesthetizing gas to a patient in preparation for surgery. In these and other applications, the flow rate control mechanism typically detects the flow of fluid traveling down a flow channel. It is desirable to reduce the noise associated with detecting the flow of fluid, particularly in low flow applications.